Graphene is a single, one atomic layer of carbon atoms with several exceptional electrical, mechanical, optical, and electrochemical properties, earning it the nickname “the wonder material.” To name just a few, it is highly transparent, extremely light and flexible yet robust (high mechanical strength), and an excellent electrical and thermal conductor. In addition, its unique 2D hexagonal lattice structure with atomic-scale thickness and high aspect ratios further differentiates graphene from other types of materials. Such extraordinary properties render graphene and related thinned graphite materials as promising candidates for a diverse set of applications ranging from energy efficient airplanes to extendable electronic papers. For example, graphene based batteries may allow electric cars to drive longer and smart phones to charge faster. Other examples include graphene's ability to filter salt, heavy metals, and oil from water, efficiently convert solar energy, and when used as coatings, prevent steel and aluminum from rusting. In the longer term, thinned crystalline graphite in general promises to give rise to new computational paradigms and revolutionary medical applications, including artificial retinas and brain electrodes.
Although single layer graphene has shown all the desirable properties, making use of these properties remains challenging and requires a very good dispersion of graphene into specific material systems, for example, polymers. Due to the strong van der Waals interaction between layers of graphene, graphene nanoflakes, particularly those having low-defect basal structures, tend to aggregate to give larger particles. Such aggregation significantly lowers the achievable interface interaction between graphene and the polymer matrices, and thus limits to a great extent the achievable properties of graphene/polymer composites.